I would like to ask of your help, since I am fairly unexperienced with the technicalities of video editing. My problem is, what I imagine to be a rather common one, stuttering video after rendering, while the input files are perfectly fine and stutter-free. The task I tried to accomplish is an image overlay on the videos (it's a png, which has a lot of transparent areas), and then addig a still jpg to the end for like 10 seconds. The input videos are video game trailers, and the ones I had problems with, are all 1080p, 30 fps, and are stored in an .mp4 format. The reason why I'm not sure if the input files are the problem, because I had a case, where I managed to get stutter-free output with one file with the same parameters. Also, I would prefer not to convert the input files before further editing (I heard mp4 might be problematic) because of the loss in quality, which I assume is inevitable.
Another suspect I had was the hardware environment, which was initially my laptop. It has plenty of processing power (it has an Intel i7, quad-core, 2 GHz CPU, 8 GB RAM and an Nvidia GT525M), but the Windows install on it is rather old. However, I tried it on my recently built gaming desktop PC, which has even more power, but the stutter remained. Also I'd assume, if you don't have enought power, the rendering would just take longer, not go wrong altogether, but correct me if I'm wrong on that one. The last thing I suspect, which is the most likely, is the software I'm using. Since I believe slapping a couple iamges on a video shouldn't be too big of a task, I went with a free softwarem called VDSC Free Video Editor. Could it be that the code is just not good enough to handle such material?
Thank you in advance for your answers, and sorry if I asked a question answered a thousand times, but I found no such case where the parameters quite matched up with mine.